After you have downloaded and installed it, You need in order to set it as a Live Wallpaper:

- go to your home screen;- press the menu button on your device;- select "Wallpaper";- select "Live Wallpapers";- search and select for this Live Wallpaper"- select "Settings" to see the settings or select "Set wallpaper" to activate it.

System Requirement:

any phone that came with Android OS 2.0 or later should work fine. Anything that came with 1.5 / 1.6 may have problems